Coronary Heart Disease – Part VII: Physical Activity As Part Of A Personal Prevention Program To Combat Coronary Heart Disease

Michael Garko, Ph.D.

Host of Let’s Talk Nutrition

Introduction

“Lack of activity destroys the good condition of every human being, while movement and methodical physical exercise save it and preserve it” (Plato). Plato’s quote from over 2,000 years ago is as relevant today as it was then. Regular physical activity, whether in the form of a structured exercise program or just part of daily living routines, helps to create, sustain and reclaim health. Throughout the history of Western civilization a host of health benefits derived from physical activity have been identified, with scientific evidence supporting these benefits steadily accumulating since the 1970s (see U.S. Department of Health & Human Services, 1996, 2008).

On the flipside of the health-physical activity coin, epidemiologic studies, cohort studies, case-control studies, cross-sectional studies and clinical trials have established that physical inactivity is a major risk factor for a variety of diseases and conditions, including the following:

When it comes to cardiovascular diseases (CVDs), physical inactivity doubles the chances of developing coronary heart disease (CHD). According to the American Heart Association (2006), “the relative risk of coronary heart disease associated with physical inactivity ranges from 1.5 to 2.4, an increase in risk comparable to that observed for high blood cholesterol, high blood pressure or cigarette smoking” (p. 1). Echoing the American Heart Association (2006), the Surgeon General of the United States reported that “the risk posed by physical inactivity is almost as high as several well known CHD risk factors, such as cigarette smoking, high blood pressure, and high cholesterol” (U.S. Department of Health and Human Services, 2000, p. 22-3).

In addition to its individual impact on cardiovascular health, physical inactivity sets the stage for other well known risk factors for CHD, including obesity, diabetes, high blood pressure, high triglycerides and low levels of high density lipoproteins (see American Heart Association, 2006). High blood pressure is a good example of how physical inactivity sets into motion other risk factors for CHD. Less active, less-fit individuals have a 30%-50% increased risk of suffering from high blood pressure than those people who are physically active on a regular basis (American Heart Association, 2006).

Yet, despite the accumulated knowledge about physical activity being crucial to creating and sustaining overall and cardiovascular health, a sedentary lifestyle is one of the distinguishing features of modern, day-to-day life in the United States. Over 60% of American adults are not regularly active, with 25% of the adult population being totally sedentary during their leisure time. Only approximately 15% of U.S. adults are involved regularly (i.e., three times a week for at least 20 minutes) in vigorous physical activity during leisure time. About 22% of adults engage regularly (i.e., five times a week for at least 30 minutes) in sustained physical activity of any intensity during their leisure time (U.S. Department of Health & Human Services, 1996). The statistics for children and adolescents are not any better. Nearly 50% of American youths 12-21 years of age do not engage in regular, vigorous activity, with physical activity declining dramatically during adolescence. Twenty-five percent of young people report that they are not involved in any vigorous physical activity during their leisure time (see U.S. Department of Health & Human Services, 1996).

The May, 2013, issue of Health and Wellness Monthlyaddresses how physical activity is fundamental to preventing disease, generally, and coronary heart disease (CHD), specifically. As part of the series on coronary heart disease, a special focus will be given to the overall and cardiovascular health benefits associated with regular physical activity. Also, attention will be devoted to clarifying the meaning of certain concepts and terms used frequently in discussions about physical activity. Finally, physical activity recommendations and tips for achieving cardiovascular health and fitness will be presented.

There are three terms used in the literature and this newsletter which merit special attention because they are of particular importance to cardiovascular health and often create conceptual confusion for health consumers due to their prolific use by professionals and lay people. They are physical activity, exercise (exercise training) and physical fitness.[2]

Physical activity can be categorized in a variety of ways. One common way is to use the mechanical and metabolic processes implicated in muscle contraction. Mechanical classification includes static exercise (no movement of limbs) or dynamic exercise (movement of limbs), while the metabolic classification involves the availability of oxygen for the contraction of the muscle and includes aerobic (available oxygen) and anaerobic (unavailable oxygen) metabolism. Hence, physical activity can be categorized as either static-dynamic or aerobic-anaerobic.

Another way of categorizing physical activity is to identify the context in which it takes place. Frequent categories used here are household, occupational and leisure time. Leisure time is often subdivided further into the categories of competitive sports, recreational activities (e.g., hiking & cycling) and exercise training.

Exercise

Exercise/exercise training and physical activity are often used interchangeably. However, a more accurate approach is to define exercise as planned, structured, and repetitive bodily movement done with the goal of improving or maintaining some aspect of physical fitness.

Physical Fitness

Physical fitness refers to a set of attributes people inherently possess or achieve giving them the ability to perform physical activity. Physical fitness is important both to athletes interested in performance-related fitness and non-athletes interested health-related fitness. One common approach to physical fitness geared toward the non-athlete is to define “physical fitness as the ability to carry out daily tasks with vigor and alertness, without undue fatigue, and with ample energy to enjoy leisure-time pursuits and to meet unforeseen emergencies” (U.S. Department of Health & Human Services, 1996, p. 20). In this regard and within the context of measuring overall physical fitness for non-athletes seeking to achieve health-related fitness, cardiorespiratory fitness, muscular endurance, body composition and flexibility constitute a set of appropriate criteria.[3]

Overall Health Benefits of Regular Physical Activity

Chronic disease and premature death are inevitable consequences of a sedentary lifestyle. However, it is established firmly in the scientific literature that regular physical activity improves a person’s health in ways that can modulate and even eliminate the development of chronic diseases and conditions and extend life (see U.S. Department of Health & Human Services, 1996, 2002). In a report on Physical Activity and Health, the Surgeon General of the United States, relying on hundreds of studies, stated that “the body responds to physical activity in ways that have important positive effects on musculoskeletal, cardiovascular, respiratory, and endocrine systems” (U.S. Department of Health & Human Services, 1996, p. 5).

Established health benefits associated with regular physical activity include the following:

Reduces the risk of either becoming sick or dying prematurely from CVDs and conditions and other leading chronic conditions and diseases (e.g., cancer & diabetes)

Reduces the risk of developing colon cancer (Findings are either too inconsistent or insufficient to draw firm conclusions regarding a relationship between physical inactivity and the development of endometrial, ovarian, testicular, prostate or breast cancer)

Helps build and maintain healthy bones, muscles and joints, thereby, resulting in managing osteoarthritis better, reducing the risk of developing osteoporosis and becoming stronger so as to walk and move about without falling

Psychologically speaking, helps to lessen depression and anxiety, improve mood/state of mind and increase ability to accomplish daily tasks throughout the life span

Improves quality of life for individuals suffering from poor health by enhancing physiological and psychological well-being (see U.S. Department of Health and Human Services, 1996, 2002, 2008).

Furthermore, on average, people who are physically active tend to outlive those individuals whose day-to-day existence is sedentary.[4] Even a moderate amount (i.e., 30 minutes a day) of moderately intense physical activity on a regular basis helps prevent disease and promote physiological and psychological health for young people and adults, while lowering morbidity and mortality rates for both older and younger adults. There is “an emerging consensus among epidemiologists, experts in exercise science, and health professionals that physical activity need not be of vigorous intensity for it to improve health” (U.S. Department of Health & Human Services, 1996, p. 3).

Cardiovascular Benefits of Regular Physical Activity

In spite of their steady decline since the late 1960s, CVDs (e.g., CHD and stroke) have remained the major causes of death, disability and health care expenditures in the United States (see U.S. Department of Health & Human Services, 1996). Physical inactivity or a sedentary lifestyle is one of the major factors responsible for CVDs remaining as the number one cause of death in America since 1900 except for the year 1916.

The bad news is that a large repertoire of studies over many decades demonstrates that physical inactivity leads to diseases and unhealthy conditions of the cardiovascular system such CHD, stroke, atherosclerosis, high blood pressure, blood lipid imbalances, ischemia, angina, thrombosis and arrhythmia (see U.S. Department of Health & Human Services, 1996). The good news is research shows that regular physical activity contributes to cardiovascular health and fitness, an important factor in decreasing the risk of CVD mortality, generally, and CHD mortality, specifically. Regular physical activity can also prevent and delay the development of high blood pressure and reduce blood pressure even in people with existing hypertension, an independent risk factor for CHD (see U.S. Department of Health & Human Services, 2002). In short, people whose lifestyle includes regular physical activity lower substantially their risk for a major cardiovascular related event such as a heart attack or stroke.

Citing recent studies focusing on the link between physical inactivity and the risk of cardiovascular and other diseases, the American Heart Association presented the following findings about the impact of physical activity on the reduction of CVD, reinforcing and expanding upon benefits mentioned above:

The death rate for heart attack patients who participated in a formal exercise program was reduced by 20 percent to 25 percent.

Walking briskly for three hours a week, or exercising vigorously for 1.5 hours, will reduce coronary heart disease risk in women by 30 to 40 percent. New England Journal of Medicine, 1999

A person’s fitness level was a more important predictor of death than established risk factors such as smoking, high blood pressure, high cholesterol and diabetes.

Becoming more active can lower your blood pressure by as much as 4 to 9 points. That could mean the difference between having high blood pressure and not having it. And it’s the same reduction in blood pressure delivered by some antihypertensive medications — without the side effects. Three 10-minute periods of activity are almost as beneficial to your overall fitness as one 30-minute session. Mayo Clinic

A U.S. National Institute of Health Diabetes Prevention Program study showed that people at high risk for diabetes and heart disease who underwent intensive lifestyle change including 150 minutes a week of moderate physical activity (such as walking) lowered their cardiovascular disease risk factors more than those taking the diabetes drug metformin. High blood pressure, triglycerides and cholesterol levels all decreased significantly, and HDL “good” cholesterol rose. American Diabetes Association

Different types of structured and unstructured physical activities can improve muscular fitness, which includes such measures as muscular strength, muscular endurance, flexibility, balance, agility and coordination. While muscular fitness is important to achieving overall health-related fitness and may even contribute to heart health, endurance and body composition are of crucial importance when it comes to preserving and promoting cardiovascular health.

Endurance

Endurance or cardiorespiratory endurance (also known as cardiorespiratory capacity, aerobic power and endurance fitness) is improved by continuous physical activity involving the use of large muscles of the legs and arms. Such endurance or aerobic activity contributes to cardiovascular health by making the heart work more efficiently during physical activity and while at rest. The heart’s workload is increased either by increasing the amount of blood it pumps or making it pump at a higher blood pressure (American Heart Association, 2006c). Endurance types of physical activity such as brisk walking, jumping rope, jogging, bicycling, cross-country skiing and dancing improve the heart’s workload function and are recommended by the American Heart Association (2006c).

With endurance fitness and aerobic activities in mind, the American Heart Association offered the following set of physical activity recommendations for people with healthy hearts:

Vigorous activity for at least 30 minutes 3–4 days each week at 50–75 percent of maximum heart rate.

Moderate-intensity physical activities for 30 minutes on most (and preferably all) days of the week provide some benefits. Physical activity need not be strenuous to bring health benefits. It’s important to include activity as part of the regular routine.

Adults who maintain a regular routine of physical activity for longer periods or more intensity are likely to have greater benefits. However, don’t overdo physical activity, because too much exercise can result in injury.

Scientific evidence also supports the idea that even moderate and low-intensity activities, when performed daily, can have some long-term health benefits. They help lower the risk of cardiovascular diseases. Older adults and people with disabilities can gain significant health benefits with a moderate amount of physical activity, preferably daily (American Heart Association, 2006f, p. 1).

In identifying low intensity, endurance activities appropriate for those with heart defects, the American Heart Association made the following recommendations: “Low intensity sports like golf, baseball and doubles tennis – and activities like dancing, casual swimming, cycling and power walking – don’t put much strain on the heart. They’re fine for almost anyone with congenital heart defects. Household activities such as digging in a garden, raking leaves, mowing the grass and vacuuming are also fine. Shoveling snow isn’t a good idea” (American Heart Association, 2006c, p. 1). The American Heart Association recommends further that some people with heart defects need to limit their physical activities and avoid more strenuous exercises such as isometric exercises, weightlifting, rope climbing, sit-ups, chin-ups and pull-ups. Depending on the nature of their heart defect, the American Heart Association recommends that some heart patients avoid high-intensity sports such as basketball, competitive swimming, rowing, competitive cycling, jogging and wrestling (see American Heart Association, 2006c).

Body Composition

Body composition represents a health-related aspect of physical fitness involving the relative distribution of muscle, fat, bone, and other vital parts of the human body. The distribution of body fat is of particular importance in the development of CVD. Recent research indicates that body fat distributed more in the abdominal area, especially the intra-abdominal area, than in the gluteo-femoral (buttocks & thigh) area and total body fat are significant risk factors for CVD and diabetes, a risk factor for CHD (see U.S. Department of Health & Human Services, 1996). Although the risk is independent of obesity, it is exacerbated by the magnitude of obesity.

Physical activity, especially endurance type activity, can play an important role in managing weight, thereby, reducing the cardiovascular risk associated with the distribution of fat in the visceral area of the body and total body fat. Thus, it is recommended that health consumers suffering from weight issues include endurance fitness in their physical activity program.

The National Heart, Lung and Blood Institute’s 2004 STRRIDE (Studies of Targeted Risk Reduction interventions through Defined Exercise) study demonstrated how endurance activities assist with weight management. The study conducted over an eight month period found that participants:

Walking 30 minutes a day or 12 miles a week at 40–55 percent maximum heart rate: Lost 1 percent of body weight, lost 1.6 percent of waist measurement, lost 2 percent of body fat and gained 0.7 percent lean muscle.

Jogging at 65–80 percent of maximum heart rate for 12 miles a week: lost 1 percent of body weight, lost 1.4 percent of waist measurement, lost 2.6 percent of body fat and gained 1.4 percent lean muscle.

Jogging at 65–80 percent of maximum heart rate for 20 miles a week: lost 3.5 percent of body weight, lost 3.4 percent of waist measurement, lost 4.9 percent of body fat and gained 1.4 percent lean muscle.

Although intended for people with heart problems such as heart failure, the following exercise tips from the American Heart Association on what to do and what to avoid are appropriate for those with healthy hearts as well:

DOs…

Wear comfortable clothes and flat shoes with laces or sneakers.

Start slowly. Gradually build up to at least 30 minutes of activity, five or more times per week (or whatever your doctor recommends). If you don’t have a full 30 minutes, try two 15-minute sessions or three 10-minute sessions to meet your goal.

Exercise at the same time of day so it becomes a habit. For example, you might walk Monday through Friday from noon to 12:30 p.m.

Drink a cup of water before, during and after exercising (but check with the doctor, because some people need to limit their fluid intake).

Ask family and friends to join you. You’ll be more likely to keep exercising.

Note your activities on a calendar or in a log book. Write down the distance or length of time of your activity and how you feel after each session. If you miss a day, plan a make-up day or add 10–15 minutes to your next session.

Use variety to keep your interest up. Walk one day, swim the next time, then go for a bike ride on the weekend.

Look for chances to be more active during the day. Walk the mall before shopping, choose a flight of stairs over an escalator, or take 10–15 minute walking breaks while watching TV or sitting for some other activity.

DON’Ts…

Get discouraged if you stop for awhile. Get started again gradually and work up to your old pace.

Do isometric exercises that require holding your breath, bearing down or sudden bursts of energy. If you’re taking part in an exercise class or physical therapy, ask the leader or therapist what these are. Also avoid lifting weights and competitive or contact sports, such as football.

Engage in any activity that causes chest pain, shortness of breath, dizziness or lightheadedness. If these happen, stop what you’re doing right away.

Exercise right after meals, when it’s very hot or humid, or when you just don’t feel up to it (American Heart Association, 2006b, pp. 1-2).

Designed for people starting a structured exercise program or increasing the amount of physical activity in their daily routine, the American Heart Association created the following helpful tips for success:

If you’ve been sedentary for a long time, are overweight, have a high risk of coronary heart disease and stroke or some other chronic health problem, see your doctor for a medical evaluation before beginning a new physical activity program.

Find a convenient time and place to do activities. Try to make it a habit, but be flexible. If you miss an exercise opportunity, work activity into your day another way.

Use music to keep you entertained.

Surround yourself with supportive people.

Find a companion to exercise with you if it will help you stay on a regular schedule and add to your enjoyment.

Don’t overdo it. Do low- to moderate-level activities, especially at first. You can slowly increase the duration and intensity of your activities as you become more fit. Over time, work up to 30–60 minutes of physical activity on most days of the week.

Keep a record of your activities. Reward yourself at special milestones. Nothing motivates like success!

Pick rhythmic, repetitive activities that challenge the circulatory system and exercise at an intensity appropriate for you.

If you decide that walking is a great activity for you, choose a place that has a smooth, soft surface; that doesn’t intersect with traffic; and that is well-lighted and safe.

Because muscular adaptation and elasticity generally slow with age, take more time to warm up and cool down while exercising. Make sure you stretch slowly.

If you plan to be active more than 30 minutes, then try to drink some water every 15 minutes, especially when exercising in hot, humid conditions. As you age, your sense of thirst tends to decrease and you can’t completely rely on your internal sense of thirst (American Heart Association, 2006f, p. 1).

Conclusion

“Lack of activity destroys the good condition of every human being, while movement and methodical physical exercise save it and preserve it” (Plato). Plato’s recognition of the health benefits of “movement” and “methodical physical exercise” is especially resonant in light of what is known today scientifically about the positive impact of physical activity on overall health, generally, and cardiovascular health, specifically.

Although the focus of the May, 2013 issue of Health and Wellness Monthly was on physical activity as part of a Personal Prevention Program to maintain cardiovascular health and minimize the odds of developing and dying from CHD, it is important to recognize that decades worth of scientifically generated data reveal that physical activity in tandem with good diet and nutrition bears greatly on the prevention of chronic disease and the creation of health (see the April, 2013, issue of Health and Wellness Monthly at www.letstalknutrition.com for a discussion on diet and nutrition and cardiovascular health). This is not to say that physical activity does not have an independent or otherwise stand alone health benefit because common sense and good science demonstrate that it does. Synergistically speaking, the recognized benefits of regular physical activity on general and cardiovascular health are even more realized when fueled and fortified by nourishing dietary and nutritional practices.

The dietary and nutritional fortification of physical activity is a necessary requirement in the battle against one of the greatest nemeses to cardiovascular health in modern society, namely a sedentary lifestyle. While the benefits of physical activity have been extolled since the time of Plato, the statistics on the extent to which adults and young people are failing to live a physically active lifestyle and falling prey to CVDs are depressing. Nevertheless, thousands of daily messages about the numerous health benefits are being communicated across the country by governmental and private health agencies, healthcare experts, practitioners and consultants and hosts of radio and television health shows.

The information about the relationship between physical activity and health, especially cardiovascular health, and the recommendations and tips on how to make “movement” and “methodical physical exercise” an integral part of one’s lifestyle were offered in a persuasive spirit. Rome (and Greece for that matter) was not built in day and neither is health.

Aerobic training – Training that improves the efficiency of the aerobic energy producing systems and that can improve cardiorespiratory endurance.

Anaerobic training – Training that improves the efficiency of the anaerobic energy producing systems and that can increase muscular strength and tolerance for acid-base imbalances during high-intensity effort.

Body composition – A health-related component of physical fitness that relates to the relative amounts of muscle, fat, bone, and other vital parts of the body.

Cardiorespiratory endurance (cardiorespiratory fitness) – A health-related component of physical fitness that relates to the ability of the circulatory and respiratory systems to supply oxygen during sustained physical activity.

[1] Concepts and terms used in this newsletter are provided for the reader in an appendix. The terms and their definitions are cited from the Surgeon General’s report on Physical Activity and Health (see U.S. Department of Health & Human Services, 1996, p.21).

[3] A set of criteria designed more for measuring the performance-related fitness of athletes includes cardiorespiratory endurance and skeletal muscular endurance, skeletal muscular strength and power, along with speed, flexibility, agility, balance, reaction time, and body composition (see U.S. Department of Health & Human Services, 1996).

[4] A sedentary life is one in which there is no leisure-time physical activity such as exercises, sports, physically active hobbies in a two-week period (U.S. Department of Health & Human Services, 2002).